Part 15 radio in State Parks

In the early 1990s the NOAA Office of Sea Grant first began taking a closer look at broadcasting public information using low power AM and published a booklet called "Low Power Radio - An Effective Communication Tool for Making Waves" in 1992, and then in 1998 the Oregon Sea Grant Program along with the Oregon Parks and Recreation Department  performed a study to determine the pros and cons of broadcasting their state park information by utilizing Part 15 instead of the more expensive TIS systems. Their semi-final results of this study was published in 1999 in another booklet entitled Low Power Radio: An Antidote For Coastal Visitors Looking But Not Seeing!

A slightly updated (or alternate) version of the same can be downloaded here: http://lowpowerradio.googlepages.com/WilliamsDeYoung.pdf

A few excerpts:

This project evaluated the effectiveness of a 100 milliwatt low power radio broadcast in providing coastal resource interpretation to visitors parked at a scenic overlook. LPR is a limited broadcast range AM radio station that park visitors can tune-in on their car radio to hear pre-recorded messages.

There are several advantages of using 100 milliwatt LPR units in coastal parks instead of a 10 Watt transmitter placed along the highway... 

There is a 100 milliwatt LPR system that broadcasts within a radius of 0.5 square miles from the station,or a 10 Watt system, which broadcasts in a radius of approximately 15 square miles (DeYoung, 1992). The Federal Communications Commission (FCC) does not require licensing for the 100 milliwatt station and commercial advertisement messages are allowed. Sponsorship by a governmental organization and FCC licensing is required for a 10 Watt system. While the 100 milliwatt system can have commercial messages, music, or other sound enhancements, the 10 Watt system cannot.

Project Rationale and Objectives
While the 10 Watt system has a larger broadcast range, its use has several disadvantages. This size system costs about $10,000, requires government sponsorship and a FCC license to operate. Additionally, the 10 Watt LPR system is often used in mobile vehicle settings, where a driver or passenger must see instructional signs and locate the broadcast frequency while traveling at high speeds. Conversely, a 100 milliwatt LPR system costs about $3,500, has few restrictions and can broadcast messages in localized areas to more stationary visitors (see Table 1) (click image to enlarge)

The 100 milliwatt LPR system can have commercial or sponsor messages, so there are several avenues available to fund the purchase of additional LPR stations. One option is to have a business, or several businesses, purchase the radio unit in exchange for broadcasting a sponsorship message recognizing their contribution toward the broadcast. Another option would be to place sponsor logos on signs or brochures promoting the broadcast and/or provide recognition in the audio message itself. 

Use of 100 milliwatt broadcasts in parking areas provides greater opportunity for visitors seeing signs, attention to message content, and likely leads to greater retention of the broadcast information. Tune-in rates during the 10 Watt Forest Talk evaluations ranged from 1.3% to 8%. While the Boiler Bay project had a tune-in rate of 10% during the first week with only four signs visible, it jumped to 16% during Weeks 4 and 5, a rate which is double the highest Forest Talk listenership. The 100 milliwatt LPR stations must have an adequate number of signs displayed so visitors have the opportunity to tune in to the broadcast.
 
Whether the OPRD interest level increases enough to widen the LPR broadcast application in coastal parks remains to be seen. The Boiler Bay project results intrigued the Port of Newport and Hatfield Marine Science Visitor Center. Both locations now have a 100 milliwatt LPR station. Results from this study indicate that LPR broadcasts are a promising communication technology for providing park visitors with helpful information.